Embedded Linux Kernel

Along with the development of computer technology,communication technology and control technology,the embedded technology is developing rapidly. The choice of an appropriate embedded operating system can greatly improve the performance of the system and speed up the development of project. Embedded Linux kernel is stable and efficient,also because of its open source and abundant materials,it is widely used in the field of embedded system.ARM is the most widely used 32-bit microprocessor,and the application of Linux on ARM is one of the most popular field in embedded system,so the research object of the paper is the s3c2410 processor and Linux2.6.20 kernel. After a lot of research and practical work ,the author explores some key technologies about Linux at kernel level.Bootloader is a small section of code that runs before the kernel of the operating system,its main function are hardware initialization and prepairing a rigth environment before the running of the OS kernel. The main function of a operating system are hardware resource management and hardware abstraction,as a general operating system,the Linux kernel consists of memory management, process management,file system and device drivers. In embedded systems, memory is a scarce resource,the memory management is a basic thing for designing a operating system,and its realization depends on the hardware architecture heavily. The s3c2410 processor has a MMU ,which provides the function of virtual address translation and memory protection. The process control and management is an accordance of determining whether a software is an operating system,the running manner of process directly determines the real time performance of an operating system, and it's the most important factor for the design of an operating system. File system is the realization of data storage and management in operating system, also it is an abstract of the storage media,its lower layer is the device driver of the storage media,so, it is the necessary element of an operating system. The device driver is a communication bridge between a computer and the outside world, without input and output and all kinds of external devices, a computer will lose the meaning of its being, so device drivers has an important status in the design of an operating system. In Linux, device drivers behave as modules, they can be installed and uninstalled dynamically, also they can be compiled with the Linux core as a whole.So,to explore the principle of embedded Linux,after the introduction of the history and trend of embedded Linux,the author studied the concept,function and the main feature of Bootloader ,based on the code of U-boot.Next,the realization principle on arm of Linux's memory management,process management,system call, interrupt processing and device drivers are studied at kernel level rather than at application level. At the same time, many methods to improve the Linux kernel and some key technologies about embedded Linux are brought up,which has important meanings to the research of operating system and the development of Linux applications.Bluetooth is a short-ditance ,wireless communication technology,which is developing rapidly.After the research of the basis for Linux kernel ,a bluetooth wireless LAN is designed successfully based on ARM-Linux platform,and its performance proves that it is reasonable and feasible for Linux to be used in embedded systems.